> What the client needs me to do, I suspect without being able to confirm because my questions are “wasting their time”, is give the warehouse a place to pencil stuff in next to line items.

have you thought that maybe this is not the reason at all why they want this ? maybe they have a scanner somewhere that works better with the landscape format ? some regulation to comply with ?

I find it absolutely insufferable when you ask people to do something that you want, and they ask you why ; like, this is not at all why you're being paid unless you're in a R&D position ; if I was in your client's shoes I'd start looking for another contractor that would give me what I ask no question asked. They're paying you for your time, no? If they ask you to dig in a hole and then fill it back after you do it.